Jiaozuo brake

Generally speaking, the reason why brake discs need to be replaced is due to cracks, rather than reaching the wear limit. There are two forms of cracks; One type is cracks generated on the friction surface; Another type is cracks that occur on the heat dissipation ribs. Due to repeated heating and cooling; Fine cracks in the friction surface soil begin to develop and propagate near the thin layer of the friction surface. Therefore, cracks occur under high-speed braking or strong braking conditions. Cracks occur on the heat dissipation ribs, which are subjected to tensile, compressive, and bending effects caused by thermal expansion. This type of crack occurs under high-speed braking, strong braking, or long-term braking conditions. Among the various factors that affect the strength characteristics of brake discs, it is believed that heat from the friction surface is the main influencing factor, while pressure or centrifugal force has a smaller impact. In the high-temperature zone, the material strength of the brake disc tends to suddenly decrease. Based on temperature, thermal stress, and braking frequency, brake disc strength evaluation indicators were developed. In order to improve the strength of brake discs, the strength of brake discs was studied from the perspectives of materials and structure. The research results indicate that the strength of special forged steel brake discs is twice that of cast iron brake discs. On the other hand, the thermal stress of the radial pin type brake disc, which is not limited by thermal strain, is set to half of that of the traditional type during design. Through the improvement of materials and structure, the characteristics of Heat capacity, heat dissipation and thermal stress are improved, so that the train speed on the traditional narrow gauge line is increased to 150km/H, and the train speed on the Shinkansen line is up to 260km/H. Therefore, it is necessary to develop a brake disc with Heat capacity matching the maximum train speed, braking deceleration, braking force distribution ratio and braking frequency. To improve the strength of the brake disc, it is necessary to improve the heat dissipation effect. Because the Unsprung mass of the device is expected to decrease, the Heat capacity of the brake disc will inevitably decrease; But local heat dissipation leads to increased thermal stress, which weakens the effect of improving strength. For this reason, it is necessary to seek more effective heat dissipation methods from a structural perspective. At present, suspended brake discs are being studied, but it will be difficult to improve their Heat capacity. The most effective way to increase Heat capacity is to use heat-resistant materials. Carbon fiber has better heat resistance than special forged steel, but its disadvantages are low strength and high price. However, trends indicate that carbon fiber is promising as a brake disc material for high-speed vehicles.